"Search for unknown operator" On Start-Up After Removing Module and Shortcuts
Search for "SCREEN_OT_set_screen" (literally, a text search) in your startup files. On Windows they're located in C:\Users\[USERNAME]\AppData\Roaming\Blender Foundation\Blender\2.79\config\.
The files are "userpref.blend" and "startup.blend", you can open them with a text editor.  

First, backup these files to somewhere safe.  

Delete all the text starting from and including the first "DATA" word right before the first occurrence of your operator name, until the next "DATA" word after the last occurrence, but don't delete this last "DATA" word as it's the start of a neighbor entry.
Then save and try opening Blender. Save your user preferences and startup file from within Blender, just to make sure.